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Why Are Horses Killed When They Break a Leg?

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If you regularly watch horse racing, you’ve may have witnessed a horse euthanized on the track. Euthanization typically occurs when a horse breaks its leg during a race. But I often wonder if some of the horses that suffered a broken leg could have been treated instead of killed.

While it may seem cruel to kill an animal when it breaks a leg, it is the most humane option for the horse. This is because broken legs are very difficult to heal, and even with treatment, the horse usually doesn’t fully recover. In addition, broken legs are extremely painful, and horses are often put down to prevent suffering.

In the horse world, breaking a leg is one of the worst injuries that can happen. Unfortunately, when this does occur, the horse is often put down. In this article, I explore why horses are killed when they break a leg and see if there are other options available.

Picture of our two year old running

Why are horses put down when they break a leg?

Thoroughbreds exceed 40 mph in a race, and one wrong step typically results in a broken leg or ankle. When broken bones occur, why isn’t the horse sedated, put on a stretcher, and brought to the veterinarian?

Or, if the owner doesn’t want to spend money on a risky veterinarian procedure, why not bring the horse home and let the bone heal naturally? Does the horse have to be euthanized? Is there no other alternative?

In most cases, yes, euthanization is the only viable option because even with the best veterinary care, they generally do not recover from this type of injury. In addition, horses are typically put down because there are complications in the treatment and recovery process of a broken leg. Let’s take a closer look at some of the complications of treating broken legs in horses.

A horse needs to be immobilized for a broken leg to heal

It’s difficult to restrict injured horses’ movements during recovery. Horses are prey animals. They have survived thousands of years because they are alert and move when threatened. What does a horse perceive as a threat? Almost anything that moves or makes a sound.

Awareness of their surroundings and reacting quickly are the keys to a horse’s survival. They are designed to run and love it. Keeping a horse still is a huge obstacle to recovery.

Besides the mental and emotional aspects, a horse’s anatomy is designed for standing; they even sleep standing. If a horse lies down for too long, they develop sores. For a horse’s broken leg to heal requires little to no weight-bearing.

Immobilization adds an emotional strain on the horse; because it’s restricting a horse’s instincts to move around, so staying in one place is tough on a horse’s psyche.

Many horses refuse to comply with treatment procedures and are unable to recover. There are numerous instances of racehorses thrashing about after surgery to repair a break resulting in a reinjury to their leg. When this happens, a horse must be euthanized.

Slings aren’t a long-term option for a horse with a broken leg

Slings are sometimes used to bear weight for a horse with a leg injury. However, they can’t be used long-term because they cause bed sores and discomfort to the horse.

Horses need to put some weight on their injured leg to ensure it recovers the necessary strength to support themselves. If a horse can’t move around and use its other legs, laminitis or abscesses may develop. When this occurs, the horse will have to be euthanized.

A horse’s hoof acts as a mechanical blood pump that works when a horse takes a step. Horses have no muscles in their lower leg or foot to aid the return of blood to the heart. Therefore the hoof must assist in moving blood. A broken bone or immobilization can disrupt blood flow.

Horses may not tolerate being in a sling and struggle, injuring themselves further.
Horses like to move, but there are some with calmer dispositions that tolerate restrictive movements and raise their chances of healing.

A Horse’s weight plays a role in recovery from a broken leg.

Horses are large animals; an average-sized thoroughbred racehorse weighs over 1000 lbs. Four legs support this enormous amount of weight, and when one breaks, it’s challenging for a horse to balance on the remaining three.

The uninjured legs often develop conditions such as laminitis or abscesses caused by carrying the extra burden. Laminitis is a painful and debilitating disease that can be fatal.

Laminitis is inflammation of the soft tissue structures attaching the coffin or pedal bone of the foot to the hoof wall. The damage to the soft tissue (laminae) causes extreme pain and instability in the hoof. It can lead to complete separation and rotation of the pedal bone within the hoof wall.

Horses that have had an episode of laminitis are prone to the disease recurring in the future. Laminitis can be managed but never cured, which is why it’s essential to take preventive steps. Laminitis is what ultimately led to the death of Barbaro.

Barbaro was a three-year-old racehorse and winner of the 2006 Kentucky Derby. In the Preakness Stakes, he shattered the bones in his right hind leg. He had surgery the following day but eventually developed laminitis in his right rear leg and both front hooves.

His owners continued to treat him until it was ultimately determined that he could not be saved. He was euthanized approximately eight months after he sustained his injury.

Barbaro wins the Derby but breaks a leg in the Preakness and never recovers

A horse with a broken leg is at risk of infection.

Bone infections caused by broken legs typically occur when bacteria are introduced into the horses’ bloodstream because of a compound(open) fracture.

Compound (open) fractures occur when the end of a broken bone penetrates through the overlying skin, and sometimes the broken bone end is visible.

A horse’s skin is very thin and easily pierced by a broken bone. Compound fractures expose the horse to dirt, grass, or manure along with other environmental contaminates infected with microorganisms.

Horses with compound fractures are likely to develop a bone infection. Successful repair of compound fractures is complicated, and the prognosis is often poor.

Long bone fractures without skin penetration are prone to infection during surgery because of the length of the operation, the area damaged, the material used to repair the break, and the presence of implants. Horses with compound fractures are often euthanized,

A horse with a broken leg suffers severe pain.

A horse that suffers a leg fracture is in extreme pain both immediately after the injury and post-surgery. Drugs can be administered to give some relief, but there are drawbacks. If you give too much, the horse will want to move around and run the risk of re-injure themselves.

Pain should be managed with proper pain relief medications, but it must be done carefully to reduce the risk of overmedicating the horse. How a horse can tolerate postoperative pain is a critical factor used to determine whether or not to euthanize.

It’s costly and risky to treat a horse with a broken leg.

The cost to treat a horse that broke its leg is expensive, and the outcome is uncertain. Typically, only the most valuable racehorses are treated, and often their recovery is unsuccessful.

For example, Barbaro, the Kentucky Derby winner referenced above, had an immediate surgical repair and was provided the best care money could buy, and still had to be euthanized.

Most horse owners don’t have the resources to risk surgery to repair a broken leg, especially surgery, with a low chance of success. Further, rehabilitation facilities may not be viable or available for the horseman.

Picture of a horse galloping.

The lower leg bones of horses are the most likely to break

The most common fractures suffered by racehorses occur in the bones of the lower limbs. Breakages typically happen as a result of direct trauma from a fall. The following is a list of the most common fractures are:

Fractures of the pedal bone. 

Pedal bone fractures typically result from a horse kicking a wall or landing on an irregular surface. These fractures heal well with rest and the application of a bar shoe unless the breach involves the coffin joint.

If the coffin joint is involved, a surgical screw fixation may be used to help some of the more significant fractures to heal. Currently, my friend owns a really nice racehorse that constantly kicks his stall walls causing injuries in his lower leg joints.

Diagram of the lower legs of a horse,

Fractures of the pastern

Pastern bone fractures commonly involve the long pastern bone and typically are longitudinal and extend down from the fetlock joint. Some simple, non-displaced fractures can heal with bandaging and rest.

They often can be repaired quickly and with a lower risk of secondary complications with surgical screw fixation. Comminuted and compound pastern fractures have a poor prognosis for future competition and athletic activities, although some can heal enough to be used for breeding purposes.

Sesamoid bone fractures.

Sesamoid bone fractures are common injuries in racehorses. The sesamoid bones are two small bones that are at the back of the fetlock joint. The bones support the fetlock joint and play an essential role in the suspensory apparatus, which also includes the ligaments at the rear of the cannon bone and pastern.

The suspensory apparatus bears much of the weight of the horse and allows a horse to bear weight without using much muscle effort.  When fractures occur in the sesamoid bones, it can result in chronic or recurrent lameness.

Some sesamoid fractures at the top of the bone can be treated by surgically removing the broken tip, but breaks in the middle or bottom part of the bone are less likely to have a favorable prognosis. If the sesamoid bone is broken into several small pieces, surgery is rarely successful, and the horse is often euthanized.

Fractures of the cannon bones

Cannon bone fractures are typically longitudinal and extend into the fetlock joint. The diagnosis and prognosis are the same as for pastern fractures (see above). Occasionally a transverse fracture is presented as a result of a fall or kick. The forecast is poor, although some horses have recovered using surgical fixation with the implant of both plates and screws.

Carpal (knee) bone fractures. 

Knee fractures or chips occur on the front or sides of the bones within the carpal (knee) joints. If the chips are small, they don’t cause any signs of lameness, but most results in pain and fluid in the joints.

Knee chips are a common injury in racehorses, and most chip fractures respond well to rest, sometimes helped with an anti-inflammatory injection into the affected joint.

Some bone chips require surgical removal. Chip removal surgery is often performed arthroscopically, which is quicker and less traumatic than conventional surgery. Slab fractures will typically need to be removed or have a surgical screw fixation, depending on the size and site of the slab fracture.

Fractures of splint bones

Splint bone fractures are common and frequently occur during exercise or after a kick or fall. Most heal with rest but always leave a knot where the healing forms. Occasionally a splint fracture doesn’t heal, and the lower portion of the affected bone must be removed to alleviate the associated pain.

Fractures of the radius (forearm bone) and tibia (thigh bone). 

Stress fractures of the radius or tibia are common in these sites in young racehorses. Full recovery is possible with rest. It’s advisable to have a bone scan to confirm the diagnosis and monitor healing before exercise is resumed. Returning to exercise too early could result in a complete fracture and poor prognosis.

Fractures of the pelvis.

 Fractured pelves are a common cause of hind-limb lameness in young racehorses. Most start as stress fractures and will heal with rest and time off. Monitoring by a bone scan is essential to confirm the diagnosis and to monitor repair before exercise is resumed.

Some pelvic fractures are misdiagnosed as muscle injuries. Unfortunately, complete, displaced pelvic fractures usually necessitate euthanasia on humane grounds.

How are horses put down, (euthanized)?

The most common way a horse is euthanized is by lethal injection. The word “euthanasia” is derived from the Greek word euthanatos and translates to “easy death” in English. Most vets take this to heart and try and make the experience as painless as possible for the horse.

The typical steps are to guide the horse to a chosen location and inject it with a pain reliever, followed by a heavy dose of barbiturates that ends the horse’s life.

If your horse is standing, be careful, his reaction to the injections can vary greatly. Some horses lay down peacefully, while others jump in the air and still; others fall quickly to the ground.

A horse’s broken leg can be fixed with surgery.

Most fractures can be surgically repaired, but not all are feasible to fix. The decision to spend a vast sum of money to save your horse is difficult, and even more so if it has a special place in your heart.

Although most can be repaired, recovery is often limited; many will never return to their former level of competition and reduced quality of life. Another post-surgery consideration is the cost of rehabilitation, the risk of infections, and the expense of medications.

After surgery, the horse will require at minimum antibiotics and pain medications. And dosage is based on weight, so expect to spend a lot of money.

Common Surgical Procedures Used to Repair a Racehorses’ Broken Leg.

  • Internal fixation: An internal fixation is the placing of screws and plates around the broken bone. The insertion of these devices allows a horse to bear full weight after surgery. Internal fixation surgery works best on repairs of one or two fractures.
  • External fixation: This is similar to the apparatus used on humans. Pins are inserted above and below the break in the bone. Then a plate is placed between the pins and attached at each end. The external fixation supports the weight of the horse, so it can stand and walk.
  • Casts: Casts are made of lightweight fiberglass and used with internal fixation to add support.
  • Gene therapy: Gene therapy is new, and researchers are experimenting with how to make fractures heal by themselves.

Below is a YouTube video depicting the fatal injury Ruffian suffered in a race.

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